FIG. 3. Specific Nel binding activity of retinal axons detected by affinity probe in situ.
(A-D) Axons from retinal explants were incubated with Nel-AP (A), AP (B), or heat-inactivated Nel-AP (HI–Nel-AP) (C). Retinal axons show strong binding activity for Nel-AP, but not for a control AP or HI–Nel-AP. No significant binding activity was detected for axons from olfactory bulb (OB) explants (D).
(E-G) Coronal sections of E12 chick tecta were treated with Nel-AP (E, F) or AP (G). Strong Nel-AP binding activity (red) is detected in the SO (E, F). In a higher magnification view (F), axon branches entering retinorecipient laminae (arrows) also show Nel-AP binding. AP did not show binding activity (G). The white dotted lines indicate the pial surface of the tectum. In (E) and (G), cell nuclei were counter-stained with DAPI (blue). Scale bars, 100 μm.